Circular knitting machine suction takeup

ABSTRACT

A method and means for producing tubular knitted fabric, as for stockings, socks or pantie hose, on a rotary cylinder circular knitting machine in which the fabric on being knitted is withdrawn upwardly from the knitting level into a receiving unit which rotates with the cylinder and on completion is withdrawn downwardly through the cylinder by reverse air flow into a lower receptacle which is stationary. A switching valve operated from the machine control means is used to switch air suction from a suction generator to the receiving unit and the lower receptacle as and when required.

United States Patent Peberdy [11] 3,826,111 July 30, 1974 [54] CIRCULARKNITTING MACHINE SUCTION TAKEUP [75] Inventor: Roland Peberdy,Leicestershire,

England I [73] Assignee: The Bentley Engineering Company Limited,Leicester, England 22 Filed: Mar. 8, 1971 21 Appl. No.: 121,649

[30] Foreign Application Priority Data Mar. 11, 1970 Great Britain11566/70 [52] US. Cl 66/14, 66/149 S [51] lnt. Cl. D041) 15/92, D04b9/10 [58] Field of Search 66/149 S, 149 R, 150, 153,

[56] References Cited 1 UNITED STATES PATENTS 1,713,736 5/1929 Bentley66/14 3,108,462 10/1963 Tcnconi.... 3,306,080 2/1967 Rossler 3,392,5517/1968 Tenconi.... 3,420,075 1/1969 Grothcy.... 3,473,350 10/1969 Scheel3,550,403 12/1970 ShieldsQ 66/150 FOREIGN PATENTS OR APPLICATIONS1,931,970 1/1970 Germany 66/14 1,934,730 1/1970 Germany 66/149 S1,245,519 9/1971 Great Britain 66/149 5 707,880 6/1966 ltaly 66/149 S713,251 9/1966 Italy 66/149 R 1,411,420 8/1965 France 66/149 S 1,412,1808/1965 France 66/14) S Primary Examiner-Wm. Carter Reynolds Attorney,Agent, or Firm-Robert E. Burns; Emmanuel J. Lobato; Bruce L. Adams [5 7]ABSTRACT A method and means for producing tubular knitted fabric, as forstockings, socks or pantie hose, on a rotary cylinder circular knittingmachine in which the fabric on being knitted is withdrawn upwardly fromthe knitting level into a receiving unit which rotates with the cylinderand on completion is withdrawn downwardly'through the cylinder byreverse air flow into a lower receptacle which is stationary. Aswitching valve operated from the machine control means is used toswitch air suction from a suction generator to the receiving unit andthe lower receptacle as and when required.

8 Claims, 3 Drawing Figures Lima PATENTEDJUUUIQH 3,826.11 1

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sum 3 or 3 FIGB.

CIRCULAR KNITTING MACHINE SUCTION TAKEUP The invention is forimprovements inthe production of knitted articles of footwear, theexpression articles of footwear being used herein in a broad sense toinclude stockings, socks, three quarter hose, pantie hose and similararticles worn on the foot. The invention is concerned with the provisionof a convenient procedure and means for practising it in which articlesof footwear or tubular blanks for forming such articles are withdrawnfrom the needles of a circular knitting machine on which they areproduced in a manner which offers a number of advantages which may beneeded for a variety of reasons in connection with the manufacture ofdifferent articles of footwear. In general the procedure is such thattubular fabric is withdrawn from the needles in a condition of reversalwhich may be needed for its own sake to facilitate subsequentprocessing, or may be incidental to the obtaining of other advantages aswill appear later.

In accordance with the invention there is provided a method of producinga tubular knitted fabric article for example a stocking, sock, pantiehose or a blank therefor, on a circular knitting machine having a rotaryneedle cylinder, comprising the steps of withdrawing the fabric upwardlyfrom the needles by suction through an upstanding passageway to an upperreceiving unit which rotates with the needle cylinder and, on completionof the article, sucking it downwardly by reverse air flow through theneedle cylinder into a lower receptacle. By this procedure the articleis delivered in a condition of reversal and if a subsequent operationsuch as linking or seaming is required the article is ready for theperformance thereof. On the other hand, the method will enable aconstricted welt-like closure to be formed conveniently as the laststage of knitting without trapping the earlier formed fabric in theconstriction. Further if .it is required to produce a tubular fabric ofconsiderable length this can readily be accommodated in the upperreceiving unit which rotates with the cylinder.

The invention may be practised on a machine of the opposed needlecylinder type, by causing an article being knitted to be withdrawn fromthe needles upwardly by suction through the top cylinder to the upperreceiving unit, and on completion to be sucked downwardly through thetop and bottom needle cylinders to the lower receptacle. Convenientlythe method is practised by means of an air suction system which isconnected to both the upper receiving unit and the lower receptacle andis arranged to be switched to apply suction to the upper unit during theknitting procedure and then to transfer the suction to the lowerreceptacle when an article has been completed.

ln practising the method the air flow may be obtained by connecting theinlet and outlet of an air blower unit one to the upper receiving unitand the other to the lower receptacle, and the reversal of air flow maybe secured by reversing said connection.

The invention also provides in a circular knitting machine having arotary needle cylinder equipped with needle and needles operatingmechanism for knitting tubular fabric. a fabric draw-off mechanismcomprising a rotatable fabric receiving unit positioned above and drivento rotate with the needle cylinder, a fabric takeup tube leadingupwardly to said receiving unit from leading to the upper receivingunitand the delivery the vicinity of the needle, a fabric delivery tubeextending downwards from the needle cylinder, an air suction generatorconnected by piping to the said receiving unit and by other piping tothe delivery tube, and a switching device for switching the connectionof the air suction alternatively to the receiving unit or the deliverytube as required. The fabric delivery tube may extend to a stationaryfabric receiving unit to which the piping from the switching device maybe connected.

In the application of the invention to a machine of the opposed needlecylinder type, the fabric take up tube extends through the uppercylinder and the fabric receiving unit is mounted immediately above saidupper cylinder. The fabric take-up tube may be coupled to the upperneedle cylinder to rotate therewith and may serve to impart rotation tothe upper receiving unit.

The apparatus conveniently has the switching device controlled bypattern control mechanism on the knitting machine so as to apply the airsuction to the receiving box during the knitting of a fabric article andduring its discharge from the needles, and to switch the air suction ataboutthe time of such discharge to the delivery tube.

Conveniently the air suction generator consists of a fan the outlet andinlet of which are connected to a switching valve which has portsconnected to piping tube respectively, the valve being arranged toswitch the connections from the fans so that the suction is appliedalternatively to the upper receiving unit and the delivery tube. Thepattern control mechanism aforementioned may be arranged to actuatemeans for operating the switching valve appropriately as and whenrequired.

Previously with double cylinder knitting machines knitted fabric e.g.,socks, has been drawn down through the bottom cylinder to tension andwithdrawn it either by rollers, air suction or grab mechanism etc. Thefabric is thereby delivered from the machine right side out and forlinking or seaming it is necessary for it to be reversed and aftertreatment reversed a second time to bring it right side out." In orderto eliminate the first of these reversing operations it has beenproposed to tension and deliver socks upwards so that they are theninside out. Apparatus proposed for this purpose has included a deliverytube extending vertically from the top of the knitting machine for asufficient distance to accommodate any required length of knittedarticle and extending to a receptacle at the side of the machine.

In the knitting of stockings on circular knitting machines which areorganised to close the toe ends of the stockings by constricting a weltlike portion of fabric it is the case that if the toe end of thestocking is produced last by an orthodox procedure with the fabric drawnoff downwardly from the needles, the foot fabric becomes embraced in theclosure and needs to be pulled through the constricted toe end fabric asa final step after the fabric has been cast off the needles. The needfor pulling the foot part through the constriction prevents theconstriction from being made as tight as is generally desirable, but onthe other hand offers the advantage that an anti-run band knitted beforecasting off is brought to the inside of the stocking. Due to theirbulkiness it has not been considered practicable to knit socks withclosed toes in this way for as ordinarily produced on double cylinderknitting machines they need to be knitted from welt to toe and thedifficulty of having to pull the foot through the constricted toe end isconsidered insuperable. The procedure of drawing the fabric upwardlyfromthe needles enables a closed toe sock to be produced and causes it finalanti-run band to be on the inside of the sock. Such procedure alsofacilitates the production of satisfactory closed toe stocking knittedwelt first. The method and apparatus provided by the invention areparticularly useful in facilitating manufacture of closed toe stockingsknitted welt first and also closed toe socks.

When producing hosiery for use in making up into tights or bodygarments, tubular fabric lengths of approximately feet are produced anddifficulties arise when drawing off a tube of such length as it isnecessary to prevent the fabric from twisting itself. The procedure andapparatus according to the invention are also of help in this connectionas the upward withdrawal of fabric into a receiving unit which rotateswith the needle cylinder or cylinders enables a considerable length oftubular fabric to be accommodated in a small volume during the knittingprocedure without tending to produce any twisting of the fabric tube.Afterwards when the fabric is drawn downwardly through the needlecylinder or cylinders there is no tendency to twisting as the fabric hasbeen cast off the needles.

Briefly described a convenient embodiment of the invention consists of acircular knitting machine for producing socks or stockings or blanks forstocking tights having situated above the needle cylinder or cylinders ahose receiving unit. Said unit revolves with the needle cylinder orcylinders and has in its upper region a foraminous barrier to restrainthe hose yet allow the passage of air which during the knitting issucked out of the top of the unit by a fan. After completion of theknitting of the article it is cast off the needles and the air flow isthen reversed, the sock or blank or stocking being thereby ejected downand out through the bottom of the needle cylinder or cylinders.Preferably matters are so arranged that at the time of press-off the airflow is reversed before the entire article is sucked into the receivingunit, thus ensuring that a lead in of fabric is provided to start thefabric back down through the cylinder.

An example of a convenient apparatus and procedure in accordance withthe invention is illustrated by way of example in the accompanyingdrawings and will now be described with reference to the drawings inwhich:

FIG. I is a schematic diagram in elevation of a knitting machine of theopposed needle cylinder type embodying the invention;

FIG. 2 is an enlarged detailed elevation view in central cross sectionof the arrangement of the cylinders and certain related parts, and

FIG. 3 is an outside elevation view of the machine showing in particularthe controlling means for certain of the parts.

Referring firstly to FIG. 1 the upper and lower needle cylinders of anopposed cylinder circular knitting machine are shown at l and 2 and aresupported in the normal fashion from fixed parts of the machineconsisting of a top plate and bed plate diagrammatically represented at3 and 4. Mounted on the top of the upper needle cylinder 1 and arrangedto rotate with it is a receiving unit comprising a chamber 5 which has abarrier or 4 screen 6 of wire mesh or other form situated high up insidethe unit preferably at its largest diameter. This barrier 6 whilstpreventing an article being knitted such as a sock, stocking or blank,shown at 7, from further displacement will always allow air toflow'through it. The unit hasa journal 8 at its top end so that it canengage in a substantially airtight manner around, and freely rotate on,a stationary pipe 9. v

A suction generator consisting of a motor and fan unit is shown at 10having an air intake pipe 11 and an air outlet pipe 12, both of whichare connected to a four way'valve box 13. A third pipe leading to thevalve box 13 is the previously mentioned pipe 9 which is connected tothe top of the receiving unit 5. A fourth pipe 14 is connected at oneend to valve box 13 and opens at its other end into a stationaryreceiving receptable or chamber 15 below the needle cylinders. A fabricdelivery tube l6 extends from below the lower needle cylinder 2 into thereceiving chamber 15. For easy removal of the knitted articles from thischamber 15 there is a trap 17 which is normally held closed by clip 18.A valve 13a in the valve box 13 has two operative positions one of whichis shown in full lines in FIG. 1 and the other in chain lines. The valveis moved from one operative position to the other at the dictates of asignal from the main control drum of the machine as described later.

During the knitting of a sock the valve 13a is in the position shown infull lines in FIG. 1 causing the air flow from the fan unit 10 to passfrom the chamber 15 up through the tube 16, needle cylinders 2 and 1,receiving unit 5, pipe 9 and through valve box 13 into pipe 11 to thefan unit 10. The other side of valve 13a allows a free passage of airfrom the fan unit 10 into the chamber 15 through the pipes 12 and 14.This condi tion is maintained sucking upwardly the article 7 beingknitted to tension it.

At the time the article 7 is being cast off the needles the valve 13a isturned to the position shown in chain lines in FIG. 1. In this positionair is sucked from chamber 15 through the pipes 14 and 12 to the fanunit 10. From the fan unit 10 air is blown through the pipes 11 and 9and down through the receiving unit 5, the needle cylinders l and 2 andtube 16 into the chamber 15. The air current causes the knitted article7 to be blown down through the needle cylinders l and 2 and tube 16 intothe chamber 15.

By the procedure described a tubular knitted footwear article is ejectedinto the collecting chambers 15 in an inside out condition so that anopen toe blank is ready for seaming or linking the toe. In the case ofan article made with a constricted welt-like toe closure knitted as itslast operation followed by an anti-run tab, the article is ejected intochamber 15 inside-out but with the anti-run tab outside the reversedsock causing it eventually to be, as desired, on the inside of the sock.

FIG. 2 shows details of the construction and mounting of the coaxialneedle cylinders l and 2 and it will be seen that the construction is inthe main quite orthodox. Thus pillars 20 support the top plate 3 fromthe bed plate 4, and the plates 3 and 4 carry anti-friction bearings 23and 24 to support the cylinders rotatably. A driving shaft 29 mounted inbearings in the bed plate 4 and top plate 3 drives the cylinders inunison through gears 27 and 28 and gear rings 25 and 26. Other knownparts shown are cam boxes 30 and 31 for the control of the needlemovements, inside sinkers 32 for the bottom cylinder, verge bits 33 forthe top cylinder, and a throat tube 34 from which the takedown tube 16depends.

An upper supporting plate 21 on pillars 22 upstanding from the plate 3carries the receiving unit 5. The passageway leading to the latterthrough the upper cylinder 1 isprovided by an inner tube 35 which servesas a mounting for a ring 36 carrying-the verge bits 33, being clamped tothe ring 36 by an enlarged end of tube 35 being gripped between a washer37 and the ring 36 by screws v38. The purpose of thus mounting the vergebits 33 is to enable them to be raised bodily together at certain timesby raising the tube 35 within the cylinder 1. To permit this the tubehas fitted around it a ring 39 clamped at intervals by screws 40 andhaving at spaced points depending pins 41 which are slidable up and downin holes in the cover plate of the top cylinder indicated at 42. Atother intervals around the ring 39 it is formed with downwardly directedpockets containing compression springs 43 which bear against plate 42 tourge the ring 39 and tube 35 with it in an upward direction. A lever 44pivoted between its ends at 45 to a post 46 on a bracket 47 fixed to thetop plate 3 acts to control the level of the ring 39 and tube 35. Theleft hand end of lever 44 as seen in FIG. 2, is forked at 48 to staddlethe tube 35 with clearance therefrom and each fork arm carries a roller49 between which and the ring 39 there is a thrust bearing 50 composedof upper and lower flat rings and intervening bearing rollers. Byrocking lever 44 counterclockwise the tube 35 is lowered to bring theverge bits 33 to a low operative level, and by rocking the lever 44clockwise the tube 35 is caused to be raised to lift the verge bits awayfrom the operative level. The verge bits are used in the manner ofsinkers for the formation of loops in the top cylinder and they aresometimes required to be moved out of action. as for instance whenknitting by reciprocation occurs on needles in the bottom cylinder 2.The facility for raising and lowering the tube 35 allows for this and inall positions the tube 35 is driven by engagement of the pins 41 in theholes in the cover plate 42 of the top cylinder.

As can be seen from FIG. 2 the receiving unit 5 is mounted to rotate onan upper anti-friction bearing 51 supported by the plate 21. The journal8 which allows it to rotate relative to the stationary pipe 9 passesthrough the plate 21 with-clearance and has fixed to it a ring 52between which and the plate 21 the bearing 51 is positioned. Thereceiving unit is not required to move up and down with the tube 35, andaccordingly the latter has its upper end slidable up and down within thelower part 53 of-the unit 5. A block 54 fixed to the inside of the part53 engages slidably in a vertical slot 55 in the upper end part of tube35. The engagement between block 54 and slot 55 serves to drive thereceiving unit 5 in unison with the tube 35 and the cylinders 1 and 2while permitting the up and down movement of tube 35.

The manner of operating the valve 310 and the lever 44 can be seen fromFIG. 3 in which the bottom frame which carries the bottom plate 4 isindicated at 56, and parts shown also in other Figures are identified bythe same reference numerals as previously. The bottom frame 56 supportsa rotatable control drum 57 of orthodox construction which is rackedround in known manner to bring about changes in the knitting cycle. By

studs 58, 58a and 59 on the control drum 57 levers 60 and 61 bothpivoted at 62 are operated at appropriate times in the knitting cycle.The lever 60 operates a follower such as a push rod 63 or a bowden cableto control the position of lever 44 so that when a gap occurs betweenthe cam parts 58 and 58a the lever.60 drops and allows the right handend of lever 44 to drop under the action of the compression springs 43which thus causes the tube 35 to be raised to a predetermined extent.When the lever 60 is again raised the tube 35 is lowered to lower theverge bits 33 to the operative level.

The valve 13a is fixed to a spindle 64 which is turned to move the valvefrom one to the other of its operative positions. On the spindle 64there is fixed a lever 65 connected bya link 66 to the long arm of lever61 (this being a bellcrank lever). The lever 65 is fitted with a returnspring 67. During the knitting of an article 7 the valve 13a is held byreturn spring 67 in the position shown in FIG. 1 which is the full lineposition of the parts 61, 65 and 66 in FIG. 3. When the article 7 isbeing cast off from the needles a cam such as 59 on the drum 57 rocksthe lever 61 counterclockwise against the action of spring 67 to theposition shown in chain lines in FIG. 3 pulling the link 66 downwardlyand turning the arm 65 and spindle 64 clockwise through a right angle tobring the valve to the position shown in chain lines in FIG. 1. Thiscauses reversal of the air flow through the receiving unit 5 and thecylinders 1 and 2 to discharge the article 7 downwardly into thecontainer 15.

It will be understood that the invention may be applied to machines ofthe single cylinder or cylinder and dial type as well as to those havingopposed coaxial needle cylinders..When the upper cylinder is omitted afabric take-up tube such as 35 and receiving unit 5 are mountedcoaxially with the needle cylinder and driven to rotate in unisontherewith.

What I claim is:

1. In a circular knitting machine for knitting tubular fabric, thecombination comprising a rotary needle cylinder, means rotatablymounting said cylinder, and fabric draw off mechanism comprising arotatable fabric receiving unit comprising a rotatable chamber forreceiving fabric drawn therein by air flow, means rotatably mountingsaid receiving unit above and coaxially with the needle cylinder, afabric take up tube, means mounting said tube to lead upwardly coaxiallywith the needle cylinder to said receiving unit from the vicinity of theknitting level, means driving said receiving unit and take up tube torotate with the needle cylinder, a top stationary pipe for applyingsuction to said fabric receiving unit to draw fabric upwardly from theknitting level into said unit, a foraminous barrier extending acrosssaid chamber of said receiving unit to permit flow of air'through saidforaminous barrier to said top pipe while preventing the passage offabric therethrough, said pipe having an end part above and coaxial withsaid receiving unit and a bearing journal connecting said end part tosaid receiving unit, a fabric collecting receptacle, a fabric deliverytube extending downwards from the needle cylinder to said collectingreceptacle, an air suction generator having inflow and outflow ports, anair flow reversing valve having intake and return ports and two furtherports interchangeably connectable to said intake and return ports,piping connecting said intake and return ports respectively to theoutflow and inflow ports of said air suction generator, means connectingsaid two further ports of the reversing valve respectively to said topstationary pipe and to said collecting receptacle, and means foroperating said valve in timed relation to programming of said knittingmachine to apply suction through said top stationary pipe to saidreceiving unit during the knitting of a piece of fabric to draw saidfabric from the knitting level into said receiving unit as the fabric isbeing knit and to store it in said receiving unit until the knitting ofa piece of fabric is completed whereupon said valve is reversed to applysuction to said collecting receptacle to draw said piece of fabric outof said receiving unit and through said take-up tube and said deliverytube down I into said collecting receptacle.

2. The combination as claimed in claim 1, wherein the collectingreceptacle is stationary.

3. The combination as claimed in claim 1 in a machine of the opposedneedle cylinder type having a lower cylinder and an upper cylinder,wherein said needle cylinder is the lower cylinder of the machine andthe mounting means for the fabric take up tube comprises the upperneedle cylinder through which the take up tube extends, and wherein thefabric receiving unit is mounted immediately above said upper cylinder.

4. The combination as claimed in claim 3 including a carrier mounted onthe lower end of the fabric take up tube to support verge bits atpositions interposed between needle tricks in the upper needle cylinder,and means for raising and lowering said carrier to raise and lower thelevel of verge bits thereon.

5. The combination as claimed in claim 4 in which said driving meansincludes means coupling the receiving unit rotationally to the take uptube whilst permitting up and down sliding movement between them, andmechanism actuable from patterning means at required times to raise andlower the take up tube and with it the verge bit carrier.

6. The combination as claimed in claim 1, wherein said rotatable chamberhas a portion of larger diameter than said take up tube, said foraminousbarrier extending across said chamber at said portion of largerdiameter.

7. The combination as claimed in claim 1, wherein said rotatable chamberhas a lower portion with upwardly diverging walls and an upper portionwith upwardly converging walls.

8. The combination as claimed in claim 7, wherein said foraminousbarrier comprises a screen extending across said chamber between saidupper and lower por-

1. In a circular knitting machine for knitting tubular fabric, thecombination comprising a rotary needle cylinder, means rotatablymounting said cylinder, and fabric draw off mechanism comprising arotatable fabric receiving unit comprising a rotatable chamber forreceiving fabric drawn therein by air flow, means rotatably mountingsaid receiving unit above and coaxially with the needle cylinder, afabric take up tube, means mounting said tube to lead upwardly coaxiallywith the needle cylinder to said receiving unit from the vicinity of theknitting level, means driving said receiving unit and take up tube torotate with the needle cylinder, a top stationary pipe for applyingsuction to said fabric receiving unit to draw fabric upwardly from theknitting level into said unit, a foraminous barrier extending acrosssaid chamber of said receiving unit to permit flow of air through saidforaminous barrier to said top pipe while preventing the passage offabric therethrough, said pipe having an end part above and coaxial withsaid receiving unit and a bearing journal connecting said end part tosaid receiving unit, a fabric collecting receptacle, a fabric deliverytube extending downwards from the needle cylinder to said collectingreceptacle, an air suction generator having inflow and outflow ports, anair flow reversing valve having intake and return ports and two furtherports interchangeably connectable to said intake and return ports,piping connecting said intake and return ports respectively to theoutflow and inflow ports of said air suction generator, means connectingsaid two further ports of the reversing valve respectively to said topstationary pipe and to said collecting receptacle, and means foroperating said valve in timed relation to programming of said knittingmachine to apply suction through said top stationary pipe to saidreceiving unit during the knitting of a piece of fabric to draw saidfabric from the knitting level into said receiving unit as the fabric isbeing knit and to store it in said receiving unit until the knitting ofa piece of fabric is completed whereupon said valve is reversed to applysuction to said collecting receptacle to draw said piece of fabric outof said receiving unit and through said take-up tube and said deliverytube down into said collecting receptacle.
 2. The combination as claimedin claim 1, wherein the collecting receptacle is stationary.
 3. Thecombination as claimed in claim 1 in a machine of the opposed needlecylinder type having a lower cylinder and an upper cylinder, whereinsaid needle cylinder is the lower cylinder of the machine and themounting means for the fabric take up tube comprises the upper needlecylinder through which the take up tube extends, and wherein the fabricreceiving unit is mounted immediately above said upper cylinder.
 4. Thecombination as claimed in claim 3 including a carrier mounted on thelower end of the fabric take up tube to support verge bits at positionsinterposed between needle tricks in the upper needle cylinder, and meansfor raiSing and lowering said carrier to raise and lower the level ofverge bits thereon.
 5. The combination as claimed in claim 4 in whichsaid driving means includes means coupling the receiving unitrotationally to the take up tube whilst permitting up and down slidingmovement between them, and mechanism actuable from patterning means atrequired times to raise and lower the take up tube and with it the vergebit carrier.
 6. The combination as claimed in claim 1, wherein saidrotatable chamber has a portion of larger diameter than said take uptube, said foraminous barrier extending across said chamber at saidportion of larger diameter.
 7. The combination as claimed in claim 1,wherein said rotatable chamber has a lower portion with upwardlydiverging walls and an upper portion with upwardly converging walls. 8.The combination as claimed in claim 7, wherein said foraminous barriercomprises a screen extending across said chamber between said upper andlower portions.